Research

Aquatic ecosystems, particularly their algal communities, can serve as sentinels of environmental changes occurring at local to global scales. Our research focuses on how algae regulate the dynamics of ecosystems and how changes in the abundance of algae species can be used to diagnose sources of environmental change.

Algae as metrics of water quality and quantityAlgae are crucial early indicators of ecological changes related to habitat degradation or restoration. Species of diatoms and other algae and cyanobacteria often exhibit preferences for low or high pH, salinity and nutrient concentrations, among other factors, and can even regulate water quality. Our research focuses on these uses of algae in the Everglades and other coastal wetlands subject to sea level rise, land use change, and large-scale restoration in the context of the Florida Coastal Everglades Long Term Ecological Research Program and the Comprehensive Everglades Restoration Plan (http://www.evergladesrestoration.gov/). These microscopic life forms need to be conserved and studied as key pieces of the Everglades 'ecological puzzle'.

Drivers of diatom diversity in space and time

Diatom diversity is driven by both niche-based and stochastic processes, such as dispersal. However, at smaller spatial and temporal scales species-sorting may be a stronger driver of diatom community assembly than dispersal. For example, salinity and phosphorus are hypothesized to be the dominant drivers of diatom community structure along the freshwater-coastal gradient of the Everglades due to environmental filtering of the regional species pool based on species’ tolerance and competitive ability under changing salinity and P concentrations down the gradient.

Role of algal mats in carbon cycling

Algal mats are composed of algae, bacteria, and fungi embedded within a matrix of mucilage and detritus. These mats are foundational components of the carbon cycle as primary producers that store carbon as biomass, sequester inorganic carbon by building soil, and provide food and habitat for aquatic invertebrates and fishes. Through monitoring and experimental work on primary production and the interactions within the mats, our lab studies the current contributions of algal mats to carbon cycling and how those might change with ecosystem-wide nutrient enrichment, saltwater intrusion, and freshwater restoration. Understanding these mats is critical to assessing how whole ecosystems like the Everglades will respond to future change.

Lakes as sentinels of climate change

While much of our lab’s research focuses on coastal wetlands, we are also studying subtropical lakes in the context of research in the Global Lakes Ecological Observatory Network (http://gleon.org/). The dynamics of algae in subtropical lakes are poorly understood, which is concerning considering the rate at which these latitudes are developing and experiencing the influences of climate change. Our studies include long-term deployments of high-resolution sensors in lakes, especially Lake Annie (http://www.archbold-station.org/html/research/annie/annie.html) to help determine the drivers and consequences of algal community change at many temporal and spatial scales.